At the present time electrosurgical instruments are becoming widely used for all types of surgery. One type of an electrosurgical instrument is a surgical scalpel for cutting the tissue of a patient. Generally such an instrument consists of a body member, which is a non-conductive plastic handle adapted to be held in the surgeon's hand, and a metal conductive blade. When a switch is operated, the blade applies either (i) cutting electrical current so that the blade cuts tissue or (ii) coagulation current so that the blade stops tissue bleeding. The switch may be mounted on the handle and a cable connects the instrument to a regulated current generator, generally using high frequency or radio frequency (RF) alternating current.
Another type of an electrosurgical instrument is used only as an electrocautery device to produce coagulation, without a cutting blade.
In practice, surgeons during an operation do not like to change instruments. They will use an electrosurgical scalpel as an electrocautery device rather than change to a different instrument. However, the electrosurgical scalpel blade is frequently the wrong shape or size to be used as a cautery device. Even if the instruments' generator is switched from the current electrical wave shape and amplitude used for an electrosurgical scalpel to the current more suitable for electrocautery, the blade or top remains the same and may not be ideal for both functions.
In U.S. Pat. No. 5,484,434 to Cartmell et al an electrosurgical scalpel has two finger-operated switches mounted on its handle. The switch selects either an electrosurgical cutting current or, alternatively, an electrosurgical coagulation current,which is transmitted to the conductive blade. The blade is fixed in the handle body.
In U.S. Pat. No. 4,545,375 a handle has two finger-operated switches, one labeled "cut" and the other "coag". The blade is described as a thin knife-like tip which is held in the handle. The entire device is disposable so that it may be used for a single operation.
U.S. Pat. No. 5,290,285 discloses an electrocautery device having a tip with two conductors. In U.S. Pat. No. 4,492,832 the blades are interchangeable and are releasably supported by a central contact element. However, generally surgeons would not want to take the time and bother, during an operation, to change blades by taking one blade out and replacing it with another. If the blades are changed by the surgeon's aid or nurse, the surgeon would have to wait while the blade is being changed, which may interrupt the flow of his movements.
The above-mentioned patents are incorporated by reference herein.